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	<div id="winchm_template_title">WdbgExts Symbols</div>
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	<div id="winchm_template_content"><div id="mainSection"><p>This topic provides a brief overview of how symbols can be manipulated using the WdbgExts API.  For an overview of using symbols in the <a href="#Bookmark192">debugger engine</a>, see <a href="#Bookmark1494">Symbols</a> in the <a href="#Bookmark193">Debugger Engine Overview</a> section of this documentation.</p>
<p>To evaluate a MASM or C++ expression, use the functions <a href="#Bookmark1072"><b>GetExpression</b></a> or <a href="#Bookmark1073"><b>GetExpressionEx</b></a>.</p>
<p>To read the value of a member in a structure, use the <a href="#Bookmark1119"><b>GetFieldData</b></a> function or, if, the member contains a primitive value, <a href="#Bookmark1121"><b>GetFieldValue</b></a> can be used.  To determine the size of an instance of a symbol in the target's memory, use the <a href="#Bookmark1129"><b>GetTypeSize</b></a> function.</p>
<p>To locate the offset of a member in a structure, use the <a href="#Bookmark1120"><b>GetFieldOffset</b></a> function.</p>
<p>To read multiple members in a structure, first use the <a href="#Bookmark1130"><b>InitTypeRead</b></a> function to initialize the structure.  Then, you can use the <a href="#Bookmark1123"><b>ReadField</b></a> function to read the members with size less than or equal to 8 bytes one at a time.  For structure addresses in physical memory, use the <a href="#Bookmark1132"><b>InitTypeReadPhysical</b></a> function instead of <b>InitTypeRead</b>.  </p>
<p>There are two functions that  you can use for iterating over linked lists.  For doubly-linked lists that use the LIST_ENTRY32 or LIST_ENTRY64 structures, the function <a href="#Bookmark1124"><b>ReadListEntry</b></a> can be used to find the next and previous entries.  The function <a href="#Bookmark1133"><b>ListType</b></a> will iterate over all the entries in a linked list and call a callback function for each entry.</p>
<p>To locate a symbol near a specified address in the target's memory, use the <a href="#Bookmark1100"><b>GetSymbol</b></a> function.</p>
<p>To delete all the symbol information from the debugger engine's cache, use the <a href="#Bookmark1101"><b>ReloadSymbols</b></a> function.  To read or change the symbol path, which is used to search for symbol files, use the <a href="#Bookmark1102"><b>GetSetSympath</b></a> function.</p>
<p>Almost all symbol operations provided by the debugger engine can be executed using the <a href="#Bookmark1075"><b>Ioctl</b></a> operation <a href="#Bookmark1076"><b>IG_DUMP_SYMBOL_INFO</b></a>.  However, while being a very flexible function, it is advanced and we recommend that you use the above simpler functions where applicable.</p>
<h3><a id="additional_information"></a><a id="ADDITIONAL_INFORMATION"></a>Additional Information</h3>
<p>For a more powerful symbols API, see <a href="#Bookmark222">Using Symbols</a> in the <a href="#Bookmark204">Using the Debugger Engine API</a> section of this documentation.</p></div></div>	
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